Treatment of materials made with or containing cellulose derivatives



Patented Aug. 4, 1931 UNITED STATES PATENT. orrlcs GEORGE HOLLAND ELLIS, F SPONDON; NEAR DERBY, ENGI LAND, ASSIGNOR TO CELANESE CORPORATION OF AMERICA, A CORPORATION OF DELAWARE TREATMENT OF MATERIALS MADE WITH OR CONTAINING CELLULOSE DERIVATIVES No Drawing. Application filed March 25, 1927, Serial No. 178,504, and. in Great Britain October 28, 1926.

This invention relates to the loading of yarns or threads or woven, knitted, or other textile fabrics or other materials made of or containing artificial filaments or fibres of cellulose acetate or other organic acid esters of cellulose, for example, cellulose formate, propionate or butyrate, or cellulose ethers, for example, methyl, ethyl or benzyl cellulose, or the corresponding condensatlon products of cellulose and glycols or other polyhydric alcohols, all of which are hereinafter referred to as organic substitution products of cellulose. "The invention also relates to ribbons, films or similar products made of the aforesaid organic substitution derivatives of cellulose.

It has been found that particularly good loadings are obtainable if the loading metals be employed at least in part in the form of their thiocyanates.

Accordingly the present invention comprises a process for loading materials made of or containing organic substitution der1va tives of cellulose and particularly cellulose acetate, in which the goods are treated with a loading metal solution which contains the loading metal or metals at least partly in the form of thiocyanates.

The goods loaded according to the present invention present considerable advantages over unloaded oods. Thus for example there is a reduction of the tendency of woven fabrics to slip of circular knitted fabrics to ladder and of warp knitted fabrics to split, an increase in the fullness or volume of the. yarns, threads or fabrics resulting in improved handle or feel and in economy of the material used to produce a given result, for example in a woven fabric less ends and picks per inch will be needed to produce a given result than with unloaded materials; and the resistance to various agencies such as heat in ironing or finishing or aqueous treatments at high temperatures is increased.

It is further found that the characteristic property, possessed by cellulose acetate in particular, of absorbing basic dyestuffs and dis rsed insoluble dyestuffs is not deleteriously afiected by this process. In fact in some cases the rate of absorption is increased.

The loading metal may be fixed on the goods by treating them before or after the treatment with the loading metal solution with a suitable precipitant for the loading metal. Thus for example the treatment with the loading metal solution may be preceded or followed by the application of a solution of tannic acid, a phosphate or silicate or it may even be followed by a simple washing with water, preferably water containing -Ewample 1 l The weighting bath is prepared asfolows:-

Concentrated aqueous solutions of stannic chloride and of ammonium thiocyanate are mixed and made up with water so as to contain 280 grams of stannic chloride (Sn CL,,.5H O) and 243 grams of ammonium thiocyanate per litre. These quantities are approximately those required to yield the salt Sn(CNS) Previously scoured celluloseacetate fabric is entered into the loading bath at about 20 0., and steeped for 1 hour with occasional turning. It is then lifted, drained well and washed, first in two baths'of cold water and then in two baths of Water at 45 C. until quite free from soluble salts. The goods are next entered into a bath at 40 C. containing of sodium dihydrogen phosphate, worked for half an hour, lifted, rinsed and soaped for 20 minutes in a bath containing 2 grams perlitre of olive oil soap at C. The goods are then rinsed and may be dried or otherwise treated as desired.

By this treatment the goods are weighted to approximately 20%. Heavier weightings may be obtained by a repetition of the process.

Example 2 Previously scoured cellulose acetate fabric is entered into a bath at 20 0. containing 280 grams of stannic chloride (Sn Cl;.5H O) and 182 grams of ammonium thiocyanate per litre of liquor. These proportions represent approximately those necessary to obtain the salt Sn Cl(CNS) After steeping for 1 hour withoccasional turning, the goods are lifted, drained, washed and further treated as described in Example 1. The goods are thus given a 20-25% weighting.

Example 3 A weighting bath is made up so as to contain 280 grams of stannic chloride (Sn 01 51-1 0) and 121 grams of ammonium thiocyanate per litre of liquor, the propertions being approximatel the proportions to form the salt Sn Cl NS) Previously scoured cellulose acetate fabric is then entered into the bath at about 20 C. and steeped for 1 hour with occasionally turning. The goods are lifted, drained well and washed twice in cold water and twice in water at 45 C. until the wash water is quite 'free from chlorine and thiocyanate. They are then treated for half an hour at about 410 C. in a 12% disodium hydrogen prosphate solution which has been rendered neutral to phenolphthalein by addition of a concentrated solution of ammonium chloride. The goods are now soaped for 20 minutes in a bath containing 2 grams er litre of olive oil soap, rinsed well in so t water and dried or otherwise treated as desired. By this method the goods are 'ven a weighting of 20-25%, the lustre being well preserved.

Alternatively in a more continuous process, the dry previously scoured goods may be passed through the weighting liquor in a suitable machine and squeezed so that they retain about their own weight of liquor, and allowed to stand for about 3 hours. The goods are then washed off and the treatment repeated, the goods being finally given a phosphate treatment. This process also gives a 20-25% weighting. For heavier weightings the number of treatments in the tin bath is increased until the desired increase is obtained.

Thou h in the above examples the thiocyanate as been employed in certain definite molecular proportions with respect to the tin, the invention is not limited to such pro,- portions or of course to tin as loading metal. Further the proportion of thiocyanate may be increased so as to be in excess of that which is chemically equivalent to the whole of the loading metal. Thus for instance in the case of t1n it may be in excess of that necessary to yield the salt Sn(CNS),,. Further it will be understood that the loading metal thiocyanates may either be prepare in situ in the baths as described in the above examples or they may be prepared pr1or to addition to the loading baths.

The process of the present invention may be applied to goods composed wholly of cellulose acetate or other of the aforementioned organic substitution derivatives of cellulose, or to mixed goods, for example mixed fabrics containin yarns of wool, cotton, natural silk, artificial silk of the cellulose type, etc. or containing yarns composed of artificial filaments of cellulose acetate or otherof the aforesaid organic substitution derivatives of cellulose doubled or associated with natural fibres, artificial silks ofthe cellulose type etc.

What I claim and desire to secure by Letters Patent is 1. Process for loading materials comprising an organic substitution derivative of cellulose, comprising treating the materials with a loading metal solution containing loading metal at least partly in the form of thiocyanate.

2. Process for loading materials comprising an organic substitution derivative of cellulose, comprising treating thematerials with a loading metal solution containing loading metal at least partly in the form of thiocyanate and with a precipitant for the loading metal.

3. Process for loading materials comprising an organic substitution derivative of cellulose, comprising treating the materials with a solution containing tin at least partly in the form of thiocyanate.

4. Process for loading materials comprising an organic substitution derivative of cellulose, comprising treating the materials with a solution containing tin at least partly in the form of thiocyanate and with a precipitant for tin.

5. Process for loading materials comprising an organic substitution derivative of cellulose, comprising treating the materials with a solution containing tin at least artlyin the form of thiocyanate and with a solution of a phosphate.

6. Process for loading materials comprising cellulose acetate, comprising treating the materials with a loading metal solution containing loading metal at least partly in the form of thiocyanate.

7. Process for loading materials comprising cellulose acetate, comprising treating the materials with a loading metal solution containing loading metal at least partly. in the form of thiocyanate and with a precipitant for the loading metal.

8. Process for loading materials comprising cellulose acetate, comprising treating the materials with a solution containing tin at least partly in the form of thiocyanate.

9. Process for loading materials comprising cellulose acetate, comprising treating the materials with a solution containing tin at least partly in the form the thiocyanate and with a precipitant for tin.

10. Process for loading materials comprising cellulose acetate, comprising treating the materials with a solution containing tin at least partly in the form of thiocyanate and with a solution of a phosphate.

11. Process for loading materials comprising cellulose acetate, comprising treating the materials with a loading metal solution containing loading metal wholly in the form of thiocyanate.

12. Process for loading materials comprising cellulose acetate, comprising treating the materials with a loading metal solution containing loading metal wholly in the form of thiocyanate and with a precipitant for the loading metal.

13. Process for loading materials comprising cellulose acetate, comprising treating the materials with a solution containing tin wholly in the form of thiocyanate, washing and subsequently treating with a solution of a phosphate.

In testimony whereof I have hereunto sub.- scribed my name.

GEORGE HOLLAND ELLIS. 

